Quantitative Aptitude · Blood Relations

Family Tree and Symbol Notation Method for Blood Relations

Updated 1 October 2026

The family tree method turns a relationship statement into a diagram. You use a symbol for male, female and unknown gender, a line for marriage, a vertical line for parent-child, and place each generation on its own level. Then you read the answer from the picture instead of reasoning in your head.

Understand Family Tree and Symbol Notation Method

Blood relation questions give you a chain of statements like "A is the mother of B, and B is the brother of C." Doing this in your head causes slips. A diagram removes the guesswork.

The method uses a few fixed symbols. These symbols are a convention, not a standard prescribed by ICAI, so you can change them. A square (or +) stands for a male. A circle (or −) stands for a female. A triangle or a plain letter with ? stands for a person whose gender is not known yet. Use whichever symbols you like, but use them the same way every time.

Lines carry meaning. A horizontal double line (=) joins a married couple. A vertical line going down joins a parent to a child. Siblings (brothers and sisters) are drawn side by side on one level, all under the same parent line. This gives you the generation: the top row is the oldest, and each row below is the next generation.

Once the tree is drawn, you only need to find the two people named in the question and read how they are connected. Same row means same generation, one row up means parent's generation, and so on. Gender then decides the exact word: uncle or aunt, nephew or niece, and so on.

Some facts cannot be fixed from the statement. If the question says "A is the sibling of B," you do not know the gender of A or B. Leave the symbol open. A good tree never assumes a gender that is not given.

Key formulas to remember

Gender symbols: □ or + = male; ○ or − = female; △ or ? = gender not known; This is a convention, not an ICAI-prescribed standard. Draw the gender only when the statement tells you. Otherwise keep it unknown.
Marriage link: A = B (double horizontal line); Husband and wife sit on the same level, so they belong to the same generation.
Sibling placement: A and B side by side on one level, under the same parent line; Brothers and sisters sit on the same level and hang from the same parent line.
Parent-child link: Parent ↓ Child (vertical line); The child is placed one level below the parent. This sets the generation.
Generation rule: Level up = older generation; same level = same generation; level down = younger generation; Spouses and siblings share a level. Parents, uncles and aunts are one level above you.
Key relation words: Father's or mother's brother = uncle; father's or mother's sister = aunt; brother's or sister's son = nephew; brother's or sister's daughter = niece; The husband of an aunt and the wife of an uncle are also called uncle and aunt. Spouse's parents are parents-in-law. Spouse's sibling is brother-in-law or sister-in-law. Your sibling's spouse is also brother-in-law or sister-in-law.
Cousin rule: Child of your uncle or aunt = cousin; A cousin is one generation level with you, with a different set of parents who are siblings.

How to solve Family Tree and Symbol Notation Method questions

Use this method for any blood relation question, from a one-line statement to a long chain.

1Read the whole question once and note who the question asks about. Underline the two people whose relation you must find.
2Start with the person whose gender or position is clearest. Place the first symbol on the page and mark its gender if known.
3Add one statement at a time. For each, decide if the new person is a spouse, sibling, parent or child, and draw the correct line.
4Put each person on the correct generation level. Parents go above, children below, spouses and siblings on the same level.
5Mark the gender only when it is given or forced by the words (father, sister, wife). Leave it open for words like sibling, cousin, child or spouse of an unknown person.
6When the tree is complete, find the two people from step 1. Count the levels between them and trace the path of lines.
7Convert the path to a relationship word using the gender of the second person. Check your answer against all four options and pick the one that matches exactly.

Quickest way: One-pass sketch with initials

When to use it: Use this for most MCQs where there are two to five statements. Skip very long chains with heavy gender uncertainty until you have finished the easier questions.

Write only the first letter of each name. Use + for male and − for female next to it, for example A+ or B−.
Draw the tree in rough pencil on the rough sheet. Do not make it neat. Keep generations on separate horizontal rows.
Work from the end of the statement backward when it says "X is the son of the father of Y". Start from Y, go up to the father, then down to X.
Translate "my father's only son" as myself if I am male; if I am female it is my brother. Check whether the question says "only", "only son" or "only daughter", since this decides if the person could be you.
Eliminate options that have the wrong generation first. Then eliminate those with the wrong gender. This usually leaves one answer.
If the gender stays unknown after the tree is complete and an option says "cannot be determined", choose it only after you check that no statement fixes the gender.
If a question is taking longer than about a minute and a half, mark it and move on. Wrong answers cost 0.25 marks each.

Common mistakes in Family Tree and Symbol Notation Method

Assigning a gender that the question never gave
Words like cousin, sibling, child or spouse feel gendered, so students fill in a gender automatically.
Fix: Draw a neutral symbol for these words. Fix the gender only when a word like son, wife, uncle or sister is used.
Putting people on the wrong generation level
Students draw people in the order they appear in the sentence instead of by relation.
Fix: Before placing a person, ask: parent, child, sibling or spouse of whom? Then place them one level up, one down, or on the same level.
Confusing father's sister with mother's sister, or the in-law types
Students rush and skip the side of the family (paternal or maternal) when drawing the line.
Fix: Draw both parent lines whenever uncle, aunt or cousin appears. Label the side next to the line.
Treating "my father's son" as always a brother
It sounds like a different person, but the speaker can be that son.
Fix: Check for words like "only". "My father's only son" is the speaker if the speaker is male. If the speaker is female, it is her brother.
Reading the relation in the wrong direction
"A is the son of B" and "A is the father of B" are easy to flip in a hurry. The question may also ask how B is related to A, not A to B.
Fix: Write "asked: X to Y" at the top of your sketch. Read the final answer as what X is to Y, not the reverse.
Choosing "cannot be determined" too early or too late
Students either give up when a gender is open or force an answer by assuming.
Fix: Finish the tree first. If the final word needs a gender that no statement gives, then the answer is "cannot be determined". Otherwise, read it off.

Worked examples

Example 1

Pointing to a man, Rekha said, "He is the son of my mother's only son." How is the man related to Rekha? (A) Brother (B) Nephew (C) Cousin (D) Uncle

Show the solution

Rekha is female. Draw her on the middle level as a circle.
Her mother is one level above. Draw the mother above Rekha.
The mother's only son is Rekha's brother. Place him on Rekha's level, beside her under the same parent line.
The man is the son of that brother. Draw him one level below the brother.
The man is the son of Rekha's brother, so he is Rekha's nephew.

Answer: (B) Nephew

Example 2

A is the husband of B. C is the daughter of A. D is the brother of B. How is D related to C? (A) Father (B) Uncle (C) Brother (D) Grandfather

Show the solution

Draw A (male) and B (female) joined by a marriage line on the top level.
C is the daughter of A. As is standard in such questions, we take C as the child of both A and B, so B is C's mother. Draw C one level below them.
D is the brother of B, so D is placed beside B on the same level, as B's sibling.
D is the brother of C's mother, so D is C's maternal uncle.
D is one generation above C and male, so the word is uncle.

Answer: (B) Uncle

Example 3

P is the father of Q. R is the sister of Q. S is the husband of R. T is the son of S and R. How is P related to T? (A) Father (B) Grandfather (C) Uncle (D) Brother-in-law

Show the solution

Draw P (male) on the top level with a vertical line down to Q.
R is the sister of Q, so R is on Q's level, also a child of P. Mark R as female.
S is R's husband. Place S on R's level, joined by a marriage line. Mark S male.
T is the son of S and R, so T is one level below R and S.
P is the father of R, and R is the mother of T, so P is T's maternal grandfather.
The mother's father is the maternal grandfather.

Answer: (B) Grandfather

Exam tips

Draw every question, even the easy ones. A ten-second sketch beats a thirty-second mental guess that goes wrong.
Look at the exact question: A to B or B to A. Many wrong answers come from reversing the direction.
Watch for the words "only", "eldest" and "unmarried". They change who can be who in the tree.
Eliminate options by generation first, then gender. This often gives the answer before the tree is complete.
Do not guess when the gender is open and "cannot be determined" is an option. Check the tree carefully, as one wrong answer costs 0.25 marks.

Practice questions from Blood Relations

Family Tree and Symbol Notation Method: frequently asked questions

How do I draw a family tree in blood relation questions?

Use a square or + for male and a circle or − for female. Join spouses with a double horizontal line. Draw parent-child links as vertical lines, and place siblings side by side on one level under the same parent line.

Is the symbol method allowed in the CA Foundation exam?

Yes. The paper is objective, and you are free to use your rough sheet in any way. Only the option you mark is checked.

What should I do when the gender is not given?

Use a neutral symbol and leave it open. Words like sibling, cousin, child and spouse do not fix a gender. If the final answer needs the gender and nothing gives it, the answer is cannot be determined.

How can I solve blood relation questions faster?

Use initials, rough sketches and one statement at a time. Eliminate options by generation and gender. Practise until common relations such as nephew, uncle and in-laws are automatic.